JP4254896B2 - Vibration cutting unit and processing apparatus - Google Patents

Description

The present invention relates to a vibration cutting unit and a processing apparatus that are suitably used for cutting a material for forming a molding die for an optical element and the like.

  There is a technique for cutting a hard material such as carbide or glass by vibrating the tip of a cutting tool such as diamond, which is called vibration cutting. This is because the cutting tool blade edge makes a fine cut at a high speed by vibration, and the cutting edge generates a chip by the vibration, so there is less stress on both the cutting tool and the work material. Cutting is realized (see, for example, Patent Documents 1, 2, 3, 4, etc.). By this vibration cutting, the critical cutting amount required in normal ductile mode cutting is improved several times, and difficult-to-cut materials can be cut with high efficiency.

  In such vibration cutting, if the vibration frequency is increased in order to improve the processing efficiency, the above-described effect is increased, and the feed rate of the tool is also increased almost in proportion to the frequency. used. In addition, since this frequency exceeds the human audible range, there is an advantage that the vibrator and the vibrator excited by the vibrator do not produce unpleasant sound.

  As a method of generating such high-speed vibration at the cutting tool blade edge, a holding member for holding the tool is excited by a piezo element or a giant magnetostrictive element, and this member is resonated by bending vibration, axial vibration, or the like. Stable vibration as a standing wave has been put into practical use. In such a method, the vibration body that supports the cutting tool is fixed by a flange-shaped support body provided on the outer periphery of the vibration body at the vibration node portion, or a screw-shaped support body at the vibration node portion. It is clamped and fixed so that it may be pinched | interposed from the circumference | surroundings by.

  However, when it is fixed by a flange-shaped support provided on the outer periphery of the vibrating body, the restraint is particularly strong against bending vibration, the predetermined vibration cutting performance cannot be obtained, the loss of vibration energy is large, or heat is generated. Problems such as an increase in the amount occur, and it is difficult to employ it particularly for flexural vibration. Therefore, in order to weaken the restraining force, a structure in which the vibrating body is fixed so as to be sandwiched between screw-like supports is desired.

  However, when the vibrating body is fixed so as to be sandwiched by the screw-shaped support, the rigidity when holding the vibrator becomes low, and when performing high-precision processing such as an optical surface, the vibration is called an uncontrollable vibration called the chatter on the processing surface. An uneven pattern is generated.

In addition, if the screw-like support that supports the vibrating body is loosened or a large amount of load is applied to the vibrator during processing, the support position of the vibrating body may change and the vibration state of the vibrator may deteriorate. It was.
JP 2000-52101 A JP 2000-218401 A Japanese Patent Laid-Open No. 9-309001 JP 2002-126901 A

  Accordingly, the present invention provides a cutting vibration body that has an appropriate restraining force against vibration displacement, can suppress the occurrence of chatter, and can suppress a change in the support position of the vibration body, and a vibration cutting incorporating the vibration body. An object is to provide a unit and a processing apparatus.

In order to solve the above problems, the vibration cutting unit according to the present invention is capable of holding a cutting tool for vibration cutting, and when holding the cutting tool, a vibrating body main body that transmits vibration to the cutting tool; In order to support a node portion of the vibrating body corresponding to at least a vibration node related to bending vibration when the vibrating body main body vibrates, the normal direction of the bending vibration surface of the vibrating body main body extends from the node portion. A cutting vibration body including a holding member that is seamlessly fixed to the node portion, a flange portion formed on a distal end side of the holding member, and the cutting vibration body, And a case member having a support portion for fixing the distal end side of the holding member, wherein the flange portion contacts the support portion from the inner surface side, and the flange portion is connected to the support portion. Having a fastening member for fixing. Here, “fixed integrally” means a state where the members are fixed substantially seamlessly and the surfaces of the members are fixed, and the vibrating body main body and the holding member are not necessarily made of the same material. It does not have to be. In addition, when a vibrating body main body and a holding member are different materials, it is contained in said integral fixation irrespective of the state from which a composition changes at the boundary of a vibrating body main body and a holding member. In addition, the “node portion” is a specified range including a vibration node at the bending vibration wavelength. The range is a circular shape having a radius of 1/10 of the wavelength centered on the node on the bending vibration surface. It is a range.

  The “node” uses, for example, a detector that detects the vibration state by placing a contact on the surface of the vibrating body, detects the vibration amplitude while the vibrating body vibrates, and the detected amplitude is the smallest. This point is a “section”.

  Further, “supporting the node portion” means supporting the same range as the node portion or a partial range in the node portion on the flexural vibration surface. Supporting a location far from the node portion forcibly fixes the location having the amplitude, increasing heat generation and reducing the vibration efficiency.

  In addition, when axial vibration is combined with bending vibration and used, it is desirable to match the axial vibration node with the position of the holding member.

  The processing apparatus according to the present invention includes (a) the above-described vibration cutting unit, and (b) a drive device that is displaced by driving the vibration cutting unit.

(A), (b), (c) is the top view of the vibration cutting unit of 1st Embodiment, a side view, and an end view. It is a top view of a vibrating body assembly. (A), (b) is the side view and end view explaining the shape of a flange part. (A), (b) is the end elevation of a tool part front-end | tip, and a top view. (A)-(j) is a figure explaining the modification of the flange part shown in FIG. (A)-(d) is a figure explaining the modification of the flange part shown in FIG. (A)-(f) is a figure explaining the modification of the flange part shown in FIG. It is a figure explaining the modification of the flange part shown to Fig.5 (a) and 5 (b). It is a block diagram explaining the processing apparatus of 2nd Embodiment. FIG. 10 is an enlarged plan view illustrating workpiece processing using the processing apparatus illustrated in FIG. 9. (A), (b) is a sectional side view of the molding die concerning a 3rd embodiment. FIG. 12 is a side sectional view of a lens formed by the molding die of FIG. 11. It is a side view explaining the front-end | tip shape of the chip | tip for a process. It is a graph explaining the surface roughness of the processed surface of 1st Example. It is a graph explaining the surface roughness of the processed surface of a comparative example. The SEM observation image of the optical element shaping die obtained with the processing method of 2nd Example is shown. It is a side view explaining the structure of the vibration body assembly of a modification.

  Next, preferred embodiments for solving the above-described problems of the present invention will be described in more detail.

  In the cutting vibration body, since the holding member that supports the node portion of the vibration body main body is integrally fixed to the root portion on the root side, the support of the vibration body body is stable, and the vibration of the vibration body body is stable. Is also stable. That is, it is possible to suppress the vibration body main body from vibrating in a mode that cannot be controlled, and the object can be processed with high accuracy by highly controlled vibration. In addition, even if a relatively large force is applied to the vibrating body, the support position of the vibrating body is unlikely to change, so that the vibration state of the vibrating body can be easily maintained, and processing consistency and reproducibility can be improved. .

In the vibration body for cutting according to the present invention, one of the features is that the holding member has fastening means for fixing on the tip side. In this case, the front end of the holding member can be reliably fixed to the case member, the driving device, and the like by the fastening means.

In yet another aspect of the present invention, the vibrator main body and the holding member are formed of a material having an absolute value of linear expansion coefficient of 2 × 10 ⁻⁶ or less (hereinafter also simply referred to as “low linear expansion material”). The In this case, since the expansion of the vibrating body main body and the holding member can be greatly reduced, the displacement of the tip of the cutting tool can be reduced and the accuracy of the cutting process can be improved. That is, when the vibration body is formed of a low linear expansion material, the expansion of the vibration body can be greatly reduced, so that, for example, the tip of the cutting tool fixed to the tip of the vibration body is greatly displaced during the cutting process. This can be prevented and the accuracy of cutting can be improved.

  In the vibration cutting unit, the vibration body of the cutting vibration body described above is held in the case member while being held via the holding member and the support portion, and the vibration state of the vibration body is protected by the case member. The object can be processed with high accuracy by controlling with high accuracy. In addition, even if a relatively large force is applied to the vibrating body, it is difficult for the position of the vibrating body to change relative to the case member, so it is easy to maintain the vibrating state of the vibrating body and improve processing consistency and reproducibility. Can do.

  In a specific aspect of the present invention, the vibration cutting unit further includes a flange portion that contacts the support portion of the case member from the inner surface side, and a fastening member for removably fixing the flange portion to the support portion. . In this case, the front end side of the holding member can be stably fixed to the case member with the flange portion being in contact with the inner surface of the case portion.

  In another aspect of the present invention, the fastening member includes a plurality of screws, and the plurality of screws fixes the support portion and the flange portion at a plurality of locations. In this case, the cutting vibrator can be attached to and detached from the case member with a simple mechanism. Furthermore, since the plurality of screws prevent the holding member from rotating, the vibration state of the vibration body is more stable.

  In yet another aspect of the present invention, the fastening member is at least one screw member erected outward from the flange portion. In this case, the cutting vibrator can be fixed and detached easily and reliably.

  In still another aspect of the present invention, the cutting vibration body includes a plurality of holding members extending from the vibration body main body, and the case member includes a plurality of support portions that respectively fix the distal ends of the plurality of holding members. In this case, the vibration body main body can be supported in the case member from a plurality of directions via the support portion, and the support of the vibration body main body can be stabilized.

  In still another aspect of the present invention, the case member is integrally formed in the main body portion including a plurality of support portions. In this case, since the relative positions of the plurality of support portions do not change mechanically, the vibration body main body is stably fixed to the case member, and the processing accuracy can be increased.

  In still another aspect of the present invention, the case member, the vibration body main body, and the holding member are formed of the same material. In this case, the linear expansion coefficients of the case member, the vibration body main body, and the holding member are matched to prevent unintentional stress from acting between the case member and the cutting vibration body, thereby improving the reliability of the vibration cutting unit. be able to.

  In still another aspect of the invention, the cutting tool further includes a cutting tool held by the vibrating body, and a fixing unit that detachably fixes the cutting tool to the vibrating body. In this case, the cutting tool can be securely fixed to the vibrating body that vibrates with high accuracy in a replaceable manner.

  In still another aspect of the present invention, a vibration source is further provided that vibrates the cutting tool through the vibrating body main body by applying vibration to the vibrating body main body. In this case, necessary vibration can be generated by supplying electric power or the like to the vibration cutting unit.

  In the above processing apparatus, since the vibration cutting unit described above is displaced by the driving device, high-precision machining can be realized by the vibration cutting unit that can control the vibration state of the vibration body main body with high precision.

  The molding die according to the present invention has a transfer optical surface for forming an optical surface of an optical element, which is created by using the vibration cutting unit described above. In this case, a mold having a concave surface and other various transfer optical surfaces can be processed efficiently and with high accuracy.

  The optical element according to the present invention is processed and created using the vibration cutting unit described above. In this case, a highly accurate optical element having a concave surface and other various optical surfaces can be obtained.

[First Embodiment]
Hereinafter, a vibration body for cutting and a vibration cutting unit according to a first embodiment of the present invention will be described with reference to the drawings. Fig.1 (a) is a top view explaining the structure of the vibration cutting unit used when processing the optical surface of the shaping die for shape | molding optical elements, such as a lens, FIG.1 (b) is FIG. FIG. 1C is a side view of the vibration cutting unit, and FIG. 1C is an end view of the vibration cutting unit. FIG. 2 is a plan view of a vibrating body assembly incorporated in the vibration cutting unit of FIG.

  As shown in FIGS. 1A to 1C, the vibration cutting unit 20 includes a cutting tool 23, a cutting vibration body 82, an axial vibrator 83, a bending vibrator 84, and a counter balance 85. And a case member 86. In addition to the cutting vibrator 82, a set of parts including the axial vibrator 83, the flexural vibrator 84, and the counter balance 85 constitutes the vibrator assembly 120. Can be regarded as an integrated cutting vibrator that vibrates in an intended state under external driving.

  Here, the cutting tool 23 is fixed so as to be embedded in the distal end portion 21 a of the tool portion 21 that is the distal end side of the vibration body 82 for cutting of the vibration cutting unit 20. As will be described in detail later, the cutting tool 23 has a cutting edge of a diamond tip, and vibrates together with the cutting vibration body 82 as an open end of the cutting vibration body 82 in a resonance state. That is, the cutting tool 23 generates a vibration that is displaced in the Z direction with the axial vibration of the cutting vibration body 82, and a vibration that is displaced in the Y axis direction with the bending vibration of the cutting vibration body 82. Among these, the flexural vibration exists in the flexural vibration plane parallel to the YZ plane in the illustrated example. As a result, the tip 23a of the cutting tool 23 is displaced at a high speed while drawing an elliptical orbit EO. In FIG. 2, the elliptical orbit EO is drawn so as to be slightly spread on the XZ plane for easy understanding, but the actual elliptical orbit EO drawn by the tip 23 a exists along a plane parallel to the YZ plane. .

The cutting vibration body 82 is a cutting vibration body integrally formed of a low linear expansion material having an absolute value of linear expansion coefficient of 2 × 10 ⁻⁶ or less. Specifically, the cutting vibration body 82 is an invar material or a super invar material. Stainless steel invar materials are preferably used. In addition, as a material of the vibration body 82 for cutting, although it becomes a comparatively big linear expansion coefficient of about 6 * 10 < ^-6 >, a cemented carbide can also be used.

Here, the invar material is an alloy containing Fe and Ni, and is an iron alloy containing 36 atomic% of Ni, but usually has a linear expansion coefficient of 1 × 10 ⁻⁶ or less at room temperature. The Young's modulus is as low as about half that of steel, but by using this as the material of the vibrating body 82, thermal expansion and contraction of the vibrating body 82 is suppressed, and the temperature drift of the cutting edge position of the cutting tool 23 held at the tip is reduced. Can be suppressed.

The super invar material is an alloy containing at least Fe, Ni, and Co, and is an iron alloy containing 5 atomic% or more of Ni and 5 atomic% or more of Co, respectively, and has a linear expansion coefficient of room temperature. In general, it is a material that is about 0.4 × 10 ⁻⁶ and is more difficult to thermally expand and contract than the above-mentioned invar. The Young's modulus is as low as about half that of steel, but by using this as the material of the vibrating body 82, thermal expansion and contraction of the vibrating body 82 is suppressed, and the temperature drift of the cutting edge position of the cutting tool 23 held at the tip is reduced. Can be suppressed.

Further, the stainless steel invar material is an alloy material in which the main component of 50 atomic% or more is Fe and the incidental material containing 5 atomic% or more is at least one of Co, Cr, and Ni. Point to. Therefore, here, Kovar material is also included in this stainless steel invar material. The stainless invar material usually has a linear expansion coefficient of 1.3 × 10 ⁻⁶ or less at room temperature. The Kovar material has a linear expansion coefficient of 5 × 10 ⁻⁶ or less at room temperature. The Young's modulus of the stainless steel invar material is as low as about half that of the steel material. By using this as the material of the vibrating body, thermal expansion and contraction of the vibrating body 82 is suppressed, and the cutting edge position of the cutting tool 23 held at the tip is reduced. Temperature drift can be suppressed. Furthermore, the stainless steel invar material has a much higher resistance to moisture than the invar material, and has an excellent feature that rust does not occur even when applied with a processing coolant or the like, so it is suitable as a structural material for holding and fixing the cutting tool 23. Yes.

  The cutting vibration body 82 includes a vibration body main body 82a that transmits vibration to the cutting tool 23, holding members 82b and 82c that support the vibration body main body 82a, and a flange portion 82e that is formed on the front end side of the holding members 82b and 82c. With. The vibrating body main body 82a is a member having the Z-axis direction as its own axial direction. In the illustrated example, the vibrating body main body 82a has a two-stage cylindrical outer shape whose diameter changes in the vicinity of the node portion NP1. However, on the assumption that the desired vibration state can be ensured, for example, a square or the like. It can be replaced with one having a cross section such as a polygon or an ellipse. The two holding members 82b and 82c extending in the ± X direction from the side wall of the vibrating body main body 82a support the vibrating body main body 82a at the node portion NP1 so as not to hinder its operation. That is, the two holding members 82b and 82c are located at the node portion and extend in the normal direction from the node portion to the bending vibration surface parallel to the YZ surface of the vibration body main body 82a. As a result, the degree of freedom of movement can be increased with respect to the flexural vibration existing in the flexural vibration plane parallel to the YZ plane as in this embodiment. For example, the restraining force provided on the outer periphery as in the prior art described above. It is possible to moderately weaken the restraining force for a large flange structure. Thereby, the loss of vibration energy can be reduced, and a predetermined cutting performance can be obtained. In the case of the illustration, both holding members 82b and 82c each have a cylindrical outer shape, but can be replaced with a member having an outer shape such as a quadrangular column or other polygonal column or an elliptical column. The base side of each holding member 82b, 82c is integrally fixed to the node portion NP1, and the front end side of each holding member 82b, 82c supports a rectangular flange portion 82e extending perpendicularly thereto. . More specifically, both the holding members 82b and 82c support the node portion NP1 of the vibration body main body 82a at the side surface positions facing each other in the X direction, and each of the holding members 82b and 82c provided on the front end side of the both holding members 82b and 82c. The end surface of the flange portion 82 e abuts on the inner surface of the case member 86 and is fixed to the case member 86. In this way, the base side of each holding member 82b, 82c is integrally fixed to the node portion NP1, so that the rigidity when the vibrator is held is increased, so that it is sandwiched between the screw-like supports of the prior art. Problems such as chattering when a vibrating body is fixed to the can be prevented. Further, it is possible to eliminate the possibility that the support position of the vibrating body changes.

  FIG. 3A is a side view of the holding members 82b and 82c and the flange portion 82e, and FIG. 3B is an end view of the flange portion 82e. The flange portion 82e has a square plate shape, and is formed with female threads FS penetrating at four locations at four corners. As shown in FIG. 1, the end of a bolt screw 91 that is a fastening member is screwed into each female screw FS through a hole TH provided corresponding to the side wall portion 86 a of the case member 86. Thereby, the end surface of the flange portion 82e is securely fixed in a state where the end surface is in contact with the inner surface of the side wall portion 86a, and the holding members 82b and 82c are precisely positioned and fixed to the case member 86. That is, the vibrating body main body 82a is fixed in a state where it is spaced from the inner surface of the case member 86 and precisely positioned and supported in the case member 86. Here, the female screw FS and the bolt screw 91 provided on the flange portion 82e serve as fastening means for fixing the tips of the holding members 82b and 82c. The thread groove and thread formed on the female screw FS and the bolt screw 91 can be selected from the normal screw direction or the reverse screw direction in consideration of prevention of loosening of the tightening. .

  The cutting vibration body 82 supported in the case member 86 by the mechanism as described above is oscillated by an axial vibrator 83 to be described later, and a resonance state is formed in which a standing wave is locally displaced in the Z direction. It becomes. In addition, the cutting vibration body 82 is also vibrated by the flexural vibrator 84 and enters a resonance state in which a standing wave that is locally displaced in the Y-axis direction is formed. Here, the node portion NP1 in which the base sides of the holding members 82b and 82c are fixed serves as a common node for the axial vibration and the flexural vibration for the cutting vibration body 82, and the axial vibration is generated by the holding members 82b and 82c. It is possible to prevent the bending vibration from being hindered.

  The holding members 82b and 82c, the flange portion 82e, and the vibration body main body 82a are integrally formed. That is, as shown in FIG. 3A, the root portions PE of the holding members 82b and 82c are fixed to the fixing portion FP of the vibrating body main body 82a without joints. For this reason, the vibration body for cutting 82 is formed by cutting a lump-shaped material, that is, a low linear expansion material such as a bar. When manufacturing the cutting vibration body 82, for example, pre-processing by a cutting device such as a milling machine and finishing processing of cutting the outer shape of the holding members 82b and 82c, the flange portion 82e, and the like into a target shape by a cutting device such as a machining center. In combination. As described above, when the vibration body main body 82a and the holding members 82b and 82c are cut out integrally, the cutting vibration body 82 can be manufactured with sufficient strength using the same material. Thereby, since the cutting vibrator 82 can be vibrated in a target state, its strength can be sufficiently increased, and its holding rigidity can be extremely increased. In this case, the flange portion 82e and the holding members 82b and 82c are somewhat inferior in terms of strength and the like, but can be fixed by welding. Note that, instead of the above-described cutting process, the cutting vibrator 82 can be manufactured by using a machining method such as grinding or electric discharge machining.

  The vibration body for cutting 82 can be integrally formed by casting instead of cutting by machining as described above. In this case, it is desirable to provide a step of precisely finishing the outer shape of each portion 82a, 82b, 82c and flange portion 82e of the cutting vibration body 82 after casting. Further, the cutting vibration member 82 is configured to vibrate the base sides of the holding members 82b and 82c by welding after fitting the base sides of the holding members 82b and 82c into the recesses and screw holes formed on the side surface of the vibration body main body 82a. It can also be fixed to the body main body 82a. Furthermore, the base sides of both holding members 82b and 82c can be directly fixed to the side surface of the vibration body main body 82a by welding without forming a recess or a screw hole on the side surface of the vibration body main body 82a.

  The axial vibrator 83 is a vibration source that is formed of a piezo element (PZT), a giant magnetostrictive element, or the like and is connected to the base side end face of the cutting vibration body 82, and vibrates via a connector, a cable, or the like not shown. It is connected to a slave drive device (described later). The axial vibrator 83 operates based on a drive signal from the vibrator driving device and gives a longitudinal wave in the Z direction to the cutting vibrator 82 by stretching and vibrating at a high frequency.

  The bending vibrator 84 is a vibration source that is formed of a piezo element, a giant magnetostrictive element, or the like and is connected to the base side surface of the cutting vibration body 82. The bending vibrator 84 is a vibrator driving device (not shown) via a connector, a cable, or the like. To be described later. The bending vibrator 84 operates based on a drive signal from the vibrator driving device, and vibrates at a high frequency to give a shear wave, that is, vibration in the Y direction in the illustrated example.

  The counter balance 85 is fixed to the opposite side of the cutting vibrator 82 with the axial vibrator 83 interposed therebetween. The counter balance 85 is a cutting vibration body integrally formed of the same material as the cutting vibration body 82. Specifically, a low linear expansion material such as an invar material, a super invar material, or a stainless invar material is used. Preferably used.

  The counter balance 85 includes a columnar vibrator body 85a that is coaxially fixed to one end of the axial vibrator 83, holding members 85b and 85c that support the node portion NP2 of the vibrator body 85a, and holding members 85b and 85c. The flange part 85e formed in the front end side of the. In the illustrated case, the vibrating body 85a has a cylindrical outer shape. However, on the assumption that the vibration mode is taken into consideration, the vibrating body main body 85a can be replaced with one having a cross section such as a rectangle or other polygons or an ellipse. The two holding members 85b and 85c extending in the ± X direction from the side wall of the vibration body 85a each have a cylindrical outer shape in the case of illustration, but have an outer shape such as a quadrangular column or other polygonal column or an elliptical column, for example. Can be replaced. The base side of each holding member 85b, 85c is integrally fixed to the node portion NP2, and the front end side of each holding member 85b, 85c supports a rectangular flange portion 85e extending perpendicularly thereto. . That is, both the holding members 85b and 85c support the node portion NP2 of the vibration body main body 85a at the side surface positions facing each other with respect to the X direction, and the flange portions 85e provided on the front end sides of the both holding members 85b and 85c. The end surface is fixed to the case member 86 by a bolt screw 91 in a state where the end surface is in contact with the inner surface of the case member 86. The shape and structure of the holding members 85b and 85c and the flange portion 85e are the same as those shown in FIGS. 3A and 3B, and the fixing method using the bolt screw 91 is also the same. The detailed explanation is omitted.

  The counter balance 85 supported in the case member 86 together with the cutting vibrator 82 by the mechanism as described above is vibrated by the axial vibrator 83 to form a standing wave that is locally displaced in the Z direction. Resonant state. Here, the node portion NP2 in which the base sides of the holding members 85b and 85c are fixed is a common node for the axial vibration and the bending vibration for the counter balance 85, and the axial vibration and the bending are caused by the holding members 85b and 85c. It is possible to prevent the vibration from being hindered.

  In the counter balance 85, the holding members 85b and 85c, the flange portion 85e, and the vibrating body main body 85a are integrally formed. In other words, the counter balance 85 is formed integrally with no joints like the cutting vibrator 82. The counter balance 85 is formed, for example, by cutting a massive material, that is, a bar. Thereby, the counter balance 85 can be vibrated in a target state, its strength can be sufficiently increased, and its holding rigidity can be extremely increased. The counter balance 85 can be integrally formed by casting. Further, the counter balance 85 may be one in which the base sides of the holding members 82b and 82c are fixed to the side surface of the vibration body main body 85a by welding.

  The case member 86 is a portion that supports and fixes the vibrating body assembly 120 including the cutting vibration body 82 and the counter balance 85. The case member 86 is for fixing the vibration cutting unit 20 to a processing apparatus (described later) for driving the vibration cutting unit 20. For this reason, a hole TH for fixing to the processing apparatus is formed at a proper position on the bottom 86b of the case member 86. Further, holes TH for fixing the flange portions 82e and 85e extending from the vibration body for cutting 82 and the counter balance 85 are also formed at appropriate positions in the pair of side wall portions 86a formed integrally with the bottom portion 86b. The portions where the holes TH are formed serve as support portions SP for supporting the cutting vibrator 82 and the counter balance 85. Here, the side wall portion 86a and the bottom portion 86b of the case member 86 are integrally formed as a main body portion without a joint. For this reason, the vibrating body assembly 120 can be precisely positioned and supported in the case member 86, not only can the support strength be increased, but the strength of the case member 86 can be sufficiently increased, and the holding thereof can be maintained. The rigidity can be extremely increased. The side wall portion 86a and the bottom portion 86b can be formed of, for example, the same material (preferably low linear expansion material) as the cutting vibration body 82. The main body portion in which the side wall portion 86a and the bottom portion 86b are integrated is formed, for example, by cutting a lump-shaped material, that is, a bar material, and can be formed integrally by casting, or can also be formed by welding a plurality of plate materials. Can do.

  A rear end plate 86 f is airtightly fixed to one end surface of the case member 86, and a front end plate 86 g is airtightly fixed to the other end surface of the case member 86. The top plate 86h is fixed in an airtight manner. An opening H1 connected to the air supply pipe 96 is formed in the rear end plate 86f, and an opening H2 through which connectors, cables, and the like extending from the vibrators 83 and 84 are also formed. The air supply pipe 96 is connected to a gas supply device (described later), and is supplied with pressurized dry air set to a desired flow rate and temperature. On the other hand, an opening H3 for allowing the tool part 21 of the vibration cutting unit 20 to pass through is formed in the front end plate 86g. In the vibration cutting unit 20 described above, the cutting vibrator 82, the axial vibrator 83, and the counter balance 85 are joined and fixed by, for example, brazing, and efficient vibration of the axial vibrator 83 is generated. It is possible. Further, a through-hole 95 is formed in the axial center of the cutting vibrator 82, the axial vibrator 83, and the counter balance 85 so as to cross these joint surfaces. Pressurized dry air from 96 circulates. That is, the through-hole 95 is a supply path for sending pressurized dry air, and constitutes a cooling means for cooling the vibration cutting unit 20 from the inside together with a gas supply device and an air supply pipe 96 (not shown). The front end portion of the through hole 95 communicates with a holding groove for inserting and fixing the cutting tool 23, and the pressurized dry air introduced into the through hole 95 can be supplied to the periphery of the cutting tool 23. Yes. Further, the tip of the through-hole 95 leaves a gap even when the cutting tool 23 is fixed, and pressurized dry air is jetted at high speed from the opening 91a formed adjacent to the cutting tool 23. Not only can the machining point at the tip of the tool 23 be efficiently cooled, but also the machining point and chips adhering to the periphery of the machining point can be reliably removed by an air flow. A part of the pressurized dry air led from the air supply pipe 96 to the case member 86 cools the vibrating body assembly 120 from the outside while passing around the vibrating body assembly 120, and the gap of the opening H <b> 3. To the outside of the case member 86.

  4 (a) and 4 (b) are a side sectional view and a plan sectional view of the tip of the tool portion 21 shown in FIG.

  As is apparent from the drawing, the tip 21a provided on the tool portion 21 has a quadrangular shape in a side view and a triangular wedge shape in a plan view. In addition, the cutting tool 23 held by the tip 21a includes a shank 23b having a triangular tip and a plate shape as a whole in plan view, and a machining tip 23c fixed to the tip of the shank 23b. Among these, the shank 23b is a support member formed of, for example, a super hard material, high-speed steel, or the like, and is difficult to bend while being lightweight. The processing tip 23c is a diamond tip, and is fixed to the tip of the shank 23b by brazing or the like. The cutting tool 23 itself is fixed so as to be embedded in the end surface 21d of the tip 21a, and the tip 23a of the processing tip 23c is disposed on the extension of the tool axis AX. Further, the processing chip 23c and the shank 23b that supports the processing chip 23c are accommodated in a wedge-shaped space having an opening angle θ extending from the wedge side surface (left and right side surfaces) of the tip portion 21a. Here, the opening angle θ of the tip end portion 21a is selected within a range of, for example, 20 ° to 90 °, and the tip shape can be appropriately changed to a semicircle, a sword tip, or the like according to the shape to be processed.

  The cutting tool 23, that is, the root portion 23e of the shank 23b is inserted in a state of fitting into a slit-like groove 21f having a rectangular cross section cut in the XZ plane along the tool axis AX from the end surface 21d of the tip 21a. In addition, the two fixing screws 25 and 26 formed of the same material as the material of the tool portion 21 are detachably and firmly fixed to the distal end portion 21a. Specifically, fixing screws 25 and 26 are sequentially screwed into fixing holes 21g and 21h penetrating between the upper and lower side surfaces of the tip 21a. These fixing holes 21g and 21h extend in the Y-axis direction, and their tightening direction is orthogonal to the tool axis AX. Both the fixing holes 21g and 21h have different inner diameters, and the inner diameter of the fixing hole 21g is larger than the inner diameter of the fixing hole 21h. Both fixing holes 21g, 21h are filled by screwing both fixing screws 25, 26. That is, deep concave portions are not left or high convex portions are not formed at the positions of the fixing holes 21g and 21h. One fixing screw 25 screwed into the fixing hole 21h is a fastening member for fixing the cutting tool 23, and is a Torx screw including a male screw portion 25b and a head portion 25a. By screwing the head portion 25a with an appropriate tool while the male screw portion 25b is inserted into the fixing hole 21g, the male screw portion 25b passes through the opening 23h formed in the root portion 23e, and the fixing hole 21g It is screwed with a female screw on the inner surface of the fixing hole 21h formed at the back. At this time, the root portion 23e of the cutting tool 23 is clamped between the head portion 25a and the inner surface of the slit-shaped groove 21f, and the root portion 23e is fixed from the main surface side, so that separation of the cutting tool 23 is prevented. Fixing of the cutting tool 23 is ensured. The other fixing screw 26 screwed into the fixing hole 21g is a so-called potato screw and functions as a locking member for preventing the fixing screw 25 from coming off. The fixing screw 26 is screwed into the fixing hole 21g by being screwed into the female screw on the inner surface of the fixing hole 21g by turning the upper end to the fixing hole 21g and turning the upper end with an appropriate tool, thereby filling the fixing hole 21g. . The fixing screw 25 is tightened from the upper end by the fixing screw 26 screwed in this way, and loosening of the fixing screw 25 is prevented. In the above, the fixing holes 21 g and 21 h and the fixing screws 25 and 26 are fixing means for fixing the cutting tool 23 to the tool portion 21.

  In the vibration cutting unit 20 of the present embodiment described above, the root portion PE of the holding members 82b, 82c, 85b, 85c for supporting the vibrating bodies 82, 85 is a shaft as shown in FIG. The joint portions NP1 and NP2 common to the directional vibration and the flexural vibration are fixed to the fixed portion FP without joints. For this reason, the node portions NP1 and NP2, that is, the vibration body main bodies 82a and 85a are securely fixed, the support of the vibration body main bodies 82a and 85a is stabilized, and the vibration of the vibration body main bodies 82a and 85a is also stabilized. That is, the vibrating body main bodies 82a and 85a can be prevented from vibrating in a mode that cannot be controlled, and the workpiece that is the object can be processed with high accuracy. Further, even if a relatively large force is applied to the vibrating body main bodies 82a and 85a, the relative position of the vibrating body main bodies 82a and 85a with respect to the case member 86 hardly changes, so that the vibrating state of the vibrating body main bodies 82a and 85a is maintained. , Process consistency and reproducibility can be improved.

  Even when the vibrating body main bodies 82a and 85a are vibrated, the base portion PE of each holding member 82b, 82c, 85b, and 85c is not subjected to a force that is displaced in the Y direction or the Z direction as described above. A twisting force acts around an axis SX parallel to the X axis due to the bending vibration. However, the amplitude of the flexural vibration is small, and it is possible to prevent the flexural vibration of the vibrating body main bodies 82a and 85a from being hindered by the elastic deformation of the holding members 82b, 82c, 85b and 85c. Here, if the base portion PE of the holding members 82b, 82c, 85b, and 85c is thinned, the possibility of suppressing the flexural vibration of the vibrating body main bodies 82a and 85a and energy loss can be reduced, but if it is too thin, the holding members 82b, There is a possibility that the strength of the vibrating bodies 82 and 85 may be reduced by extending 82c, 85b and 85c. On the other hand, if the base portion PE of the holding members 82b, 82c, 85b, and 85c is thickened, the holding members 82b, 82c, 85b, and 85c can be extended and the strength of the cutting vibrator 82 can be improved, but the vibrator main body 82a. , 85a, and the possibility of increasing the energy loss. Therefore, the size of the base portion PE of the holding members 82b, 82c, 85b, and 85c needs to be set appropriately according to the vibration state such as the frequency and amplitude when the vibrator main bodies 82a and 85a are actually operated. .

  5-7 is a figure explaining the modification of the flange part 82e shown in FIG. The flange portion 85e can be deformed similarly to the flange portion 82e. FIGS. 5A and 5B are an end view and a side view of the flange portion 182e of the first modification, respectively. The flange portion 182e has a rectangular plate shape, and is formed with female threads FS penetrating at two locations at both ends in the longitudinal direction. As in the case shown in FIG. 1, the ends of the bolt screws 91 are screwed into the female screws FS through the holes TH provided in the side wall portions 86a of the case member 86, and the end surfaces of the flange portions 182e are the end surfaces of the side wall portions 86a. The holding members 82b and 82c, that is, the vibrating body assembly 120 are precisely positioned and fixed to the case member 86 while being fixed to the inner surface. In this case, the vibrating body assembly 120 can be easily fixed to the case member 86 only by providing two holes TH for each of the holding members 82b and 82c in the side wall portion 86a.

  FIGS. 5C and 5D are an end view and a side view of the flange portion 282e of the second modification, respectively. The flange portion 282e has a disk shape and is provided with a columnar protrusion 282f at the center of the end surface. The flange portion 282e and the protrusion 282f are integrally formed, and the strength and accuracy can be easily increased. A female screw FS2 is formed at the center of the protrusion 282f along the axial center of the holding members 82b and 82c. The protrusion 282f is fitted into a hole TH provided in the side wall 86a of the case member 86. A bolt screw 91 similar to that shown in FIG. 1 is screwed into the female screw FS2. That is, the side wall portion 86a of the case member 86 is sandwiched and fixed between the flange portion 282e and the bolt screw 91, and the holding members 82b and 82c, that is, the vibrating body assembly 120 are precisely positioned and fixed to the case member 86. . Here, the female screw FS2 and the bolt screw 91 provided on the protrusion 282f are fastening means for fixing the tips of the holding members 82b and 82c. In this case, the vibrating body assembly 120 can be easily fixed to the case member 86 only by providing one hole TH for each holding member 82b, 82c in the side wall portion 86a. In this modification, one side wall 86a and bottom 86b of the case member 86 are integrally formed, but the other side wall 86a can be attached to and detached from the bottom 86b with bolts or screws. Fixed to. Thereby, the protrusions 282f extending from the tips of the holding members 82b and 82c can be inserted into the holes TH provided in the pair of side wall portions 86a.

  FIGS. 5E and 5F are an end view and a side view of the flange portion 382e of the third modification, respectively. The flange portion 382e has a square shape and is provided with four screw portions 382g projecting in a cylindrical shape at four corners. Each screw portion 382g is a screw member as a fastening member having the same shape as the screw portion of the bolt screw 91 shown in FIG. The flange portion 382e and the screw portion 382g are integrally formed, and the strength and accuracy can be easily increased. The screw portion 382g is inserted into a hole TH provided in the side wall portion 86a of the case member 86. A nut is screwed to the tip of the screw portion 382g. That is, the side wall portion 86a of the case member 86 is fixed between the flange portion 382e and a nut (not shown) screwed to the screw portion 382g, and the holding members 82b and 82c, that is, the vibrating body assembly are fixed to the case member 86. The solid 120 is precisely positioned and fixed. Here, the screw part 382g provided in the flange part 382e and the nut screwed to this are fastening means for fixing the tips of the holding members 82b and 82c. In this modification, one side wall 86a and bottom 86b of the case member 86 are integrally formed, but the other side wall 86a can be attached to and detached from the bottom 86b with bolts or screws. Fixed to. Thereby, the screw part 382g extended from the front-end | tip of both holding members 82b and 82c can be inserted in the hole TH provided in a pair of side wall part 86a.

  5 (g) and 5 (h) are an end view and a side view of the flange portion 482e of the fourth modified example, respectively. The flange portion 482e has a rectangular plate shape, and is provided with two screw portions 482g projecting in a cylindrical shape at two locations on both ends in the longitudinal direction. Each screw portion 482g is a screw member as a fastening member having the same shape as the screw portion of the bolt screw 91 shown in FIG. The flange portion 482e and the screw portion 482g are integrally formed, and the strength and accuracy can be easily increased. The screw portion 482g is inserted into a hole TH provided in the side wall portion 86a of the case member 86. A nut is screwed to the tip of the screw portion 482g. That is, the side wall portion 86a of the case member 86 is fixed between the flange portion 482e and a nut (not shown) screwed to the screw portion 482g, and the holding members 82b and 82c, that is, the vibrating body assembly are fixed to the case member 86. The solid 120 is precisely positioned and fixed. In this modification, one side wall 86a and bottom 86b of the case member 86 are integrally formed, but the other side wall 86a can be attached to and detached from the bottom 86b with bolts or screws. Fixed to. Thereby, the screw part 482g extended from the front-end | tip of both holding members 82b and 82c can be inserted in the hole TH provided in a pair of side wall part 86a.

  5 (i) and 5 (j) are respectively an end view and a side view of a flange portion 582e of a fifth modification. The flange portion 582e has a disk shape and is provided with one screw portion 582g protruding in a columnar shape at the center of the end surface. The screw portion 582g is a screw member as a fastening member having the same shape as the screw portion of the bolt screw 91 shown in FIG. The flange portion 582e and the screw portion 582g are integrally formed, and the strength and accuracy can be easily increased. The screw portion 582g is inserted into a hole TH provided in the side wall portion 86a of the case member 86. A nut is screwed to the tip of the screw portion 582g. That is, the side wall portion 86a of the case member 86 is sandwiched and fixed between the flange portion 582e and a nut (not shown) screwed to the screw portion 582g, and the holding members 82b and 82c, that is, the vibrating body assembly are fixed to the case member 86. The solid 120 is precisely positioned and fixed. In this modification, one side wall 86a and bottom 86b of the case member 86 are integrally formed, but the other side wall 86a can be attached to and detached from the bottom 86b with bolts or screws. Fixed to. Thereby, the screw part 582g extended from the front-end | tip of both holding members 82b and 82c can be inserted in the hole TH provided in a pair of side wall part 86a.

  6 (a) and 6 (b) are an end view and a side view of a sixth modification, respectively. The illustrated fixed end 682j is obtained by removing the flange portion 282e from the tip of the holding members 82b and 82c shown in FIGS. 5 (c) and 5 (d). In this case, the protrusion 682f is fitted into the hole TH provided in the side wall portion 86a of the case member 86. A bolt screw 91 similar to that shown in FIG. 1 is screwed into the female screw FS2. However, since there is nothing equivalent to the flange portion 282e, the vibrating body assembly 120 is fixed to the case member 86 by pulling the holding members 82b and 82c from the pair of side wall portions 86a provided on the case member 86. Can do. In this modification, one side wall 86a and bottom 86b of the case member 86 are integrally formed, but the other side wall 86a can be attached to and detached from the bottom 86b with bolts or screws. Fixed to. Thereby, the protrusions 682f extending from the tips of the holding members 82b and 82c can be inserted into the holes TH provided in the pair of side wall portions 86a.

  6 (c) and 6 (d) are an end view and a side view of a seventh modification, respectively. The illustrated fixed end 782j is obtained by removing the flange portion 582e from the tip of the holding members 82b and 82c shown in FIGS. 5 (i) and 5 (j). In this case, the screw portion 782g is inserted into the hole TH provided in the side wall portion 86a of the case member 86. A nut is screwed to the tip of the screw portion 782g. However, since there is no equivalent to the flange portion 582e, the vibrating body assembly 120 is fixed to the case member 86 by pulling the holding members 82b and 82c from the pair of side wall portions 86a provided on the case member 86. Can do. In this modification, one side wall 86a and bottom 86b of the case member 86 are integrally formed, but the other side wall 86a can be attached to and detached from the bottom 86b with bolts or screws. Fixed to. Thereby, the screw part 782g extended from the front-end | tip of both holding members 82b and 82c can be inserted in the hole TH provided in a pair of side wall part 86a.

  FIGS. 7A and 7B are an end view and a cross-sectional view taken along arrow AA of the flange portion 882e of the eighth modification, respectively. The flange portion 882e has a quadrangular shape, and holes VH are formed through the four corners. A bolt screw 91 shown in FIG. 1 is passed through each hole VH, and a nut 92 is fastened to the tip of the bolt screw 91. That is, the side wall portion 86a and the flange portion 882e of the case member 86 are fastened and fixed by the bolt screw 91 and the nut 92, and the holding members 82b and 82c, that is, the vibrating body assembly 120 are precisely positioned and fixed to the case member 86. The Here, the bolt screw 91 and the nut 92 are fastening means for fixing the tips of the holding members 82b and 82c.

  7 (c) and 7 (d) are an end view and a cross-sectional view taken along the arrow BB of the flange portion 982e of the ninth modification, respectively. The flange portion 982e has a rectangular plate shape, and has holes VH penetrating at two locations on both ends in the longitudinal direction. A bolt screw 91 shown in FIG. 1 is passed through each hole VH, and a nut 92 is fastened to the tip of the bolt screw 91. That is, the side wall portion 86a and the flange portion 982e of the case member 86 are fastened and fixed by the bolt screw 91 and the nut 92, and the holding members 82b and 82c, that is, the vibrating body assembly 120 are precisely positioned and fixed to the case member 86. The

  FIGS. 7 (e) and 7 (f) are an end view and a CC arrow sectional view of the flange portion 1082e of the tenth modification, respectively. The flange portion 1082e has a rectangular plate shape, and has a hole VH penetrating at one place at one end portion in the longitudinal direction. A bolt screw 91 shown in FIG. 1 is passed through the hole VH, and a nut 92 is fastened to the tip of the bolt screw 91. That is, the side wall portion 86a and the flange portion 1082e of the case member 86 are fastened and fixed by the bolt screw 91 and the nut 92, and the holding members 82b and 82c, that is, the vibrating body assembly 120 are precisely positioned and fixed to the case member 86. The

  FIG. 8 is a cross-sectional view of the flange portion 1182e of the eleventh modification, and corresponds to FIG. In this case, the holding members 82b and 82c do not extend linearly but extend in a crank shape. Note that the holding members 82b and 82c shown in FIGS. 7D and 7F can also extend in a crank shape. Further, the holding members 82b and 82c shown in FIG. 2 and the like can also be extended in a crank shape.

  Although not described in detail, not only the holding members 82b and 82c but also the holding members 85b and 85c can be similarly modified.

[Second Embodiment]
Hereinafter, a processing apparatus according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a block diagram conceptually illustrating the structure of a processing apparatus of a vibration cutting type that processes an optical surface of a molding die for molding an optical element such as a lens.

  As shown in FIG. 9, the processing apparatus 10 includes a vibration cutting unit 20 for cutting a workpiece W that is a workpiece, an NC drive mechanism 30 that supports the vibration cutting unit 20 with respect to the workpiece W, A drive control device 40 that controls the operation of the drive mechanism 30, a vibrator drive device 50 that applies desired vibration to the vibration cutting unit 20, a gas supply device 60 that supplies a cooling gas to the vibration cutting unit 20, and an apparatus And a main controller 70 that controls the overall operation in an integrated manner.

  The vibration cutting unit 20 is a vibration cutting tool in which a cutting tool 23 is embedded at the tip of a tool portion 21 extending in the Z-axis direction, and efficiently cuts the workpiece W by high-frequency vibration of the cutting tool 23. The vibration cutting unit 20 has the structure described in the first embodiment.

  The NC drive mechanism 30 is a drive device having a structure in which a first stage 32 and a second stage 33 are placed on a pedestal 31. Here, the first stage 32 supports the first movable part 35, and the first movable part 35 indirectly supports the workpiece W via the chuck 37. The first stage 32 can move the workpiece W, for example, to a desired position along the Z-axis direction at a desired speed. The first movable portion 35 can rotate the workpiece W around the horizontal rotation axis RA parallel to the Z axis at a desired speed. On the other hand, the second stage 33 supports the second movable part 36, and the second movable part 36 supports the vibration cutting unit 20. The second stage 33 supports the second movable part 36 and the vibration cutting unit 20 and can move them to a desired position along, for example, the X-axis direction or the Y-axis direction at a desired speed. Further, the second movable portion 36 can rotate the vibration cutting unit 20 at a desired speed by a desired angular amount around the vertical turning axis PX parallel to the Y axis. In particular, the vibration cutting unit 20 is positioned at its tip by arranging the tip point of the vibration cutting unit 20 on the vertical pivot axis PX by appropriately adjusting the fixed position and angle of the vibration cutting unit 20 with respect to the second movable portion 36. It can be rotated around the point by a desired angle.

  In the NC drive mechanism 30 described above, the first stage 32 and the first movable unit 35 constitute a workpiece drive unit that drives the workpiece W, and the second stage 33 and the second movable unit 36 are A tool driving unit that drives the vibration cutting unit 20 is configured.

  The drive control device 40 enables high-precision numerical control, and drives the motor, the position sensor, and the like built in the NC drive mechanism 30 under the control of the main control device 70, thereby allowing the first and first control. The two stages 32 and 33 and the first and second movable parts 35 and 36 are appropriately operated to a target state. For example, the first and second stages 32, 33 follow a predetermined locus in which the machining point at the tip of the cutting tool 23 provided at the tip of the tool portion 21 of the vibration cutting unit 20 is set at a low speed in a plane parallel to the XZ plane. Thus, the workpiece W can be rotated around the horizontal rotation axis RA at a high speed by the first movable portion 35 while moving (feeding operation) relative to the workpiece W. As a result, the NC drive mechanism 30 can be utilized as a highly accurate lathe under the control of the drive control device 40. At this time, the second movable portion 36 can appropriately rotate the tip of the cutting tool 23 around the vertical turning axis PX around the processing point corresponding to the tip of the cutting tool 23, Thus, the tip of the cutting tool 23 can be set to a desired posture (tilt).

  The vibrator driving device 50 is for supplying electric power to a vibration source built in the vibration cutting unit 20, and the tip of the tool unit 21 is controlled by the main controller 70 by a built-in oscillation circuit or PLL circuit. It can be vibrated at a desired frequency and amplitude. Note that the tip of the tool portion 21 is capable of bending vibration perpendicular to the axis (that is, the tool axis AX extending in the cutting depth direction) and axial vibration along the axis. Fine and efficient machining is possible by directing the tip of the tool portion 21, that is, the cutting tool 23, to the surface of the workpiece W due to a typical vibration.

  The gas supply device 60 is for cooling the vibration cutting unit 20, and passes a gaseous fluid source 61 for supplying pressurized dry air and the pressurized dry air from the gaseous fluid source 61. Are provided with a temperature adjusting unit 63 as a temperature adjusting unit for adjusting the temperature of the gas and a flow rate adjusting unit 65 as a flow rate adjusting unit for adjusting the flow rate of the pressurized dry air that has passed through the temperature adjusting unit 63. Here, the gaseous fluid source 61 dries air by, for example, sending the air to a dryer using a thermal process, a desiccator, or the like, and pressurizes the dry air to a desired pressure with a compressor. Although not shown, the temperature adjustment unit 63 includes, for example, a flow path in which the refrigerant is circulated around and a temperature sensor provided in the middle of the flow path. By adjusting the temperature and supply amount of the refrigerant, The pressurized dry air passed through the flow path can be adjusted to a desired temperature. Furthermore, the flow rate adjusting unit 65 has, for example, a valve and a flow controller (not shown), and can adjust the flow rate when supplying pressurized dry air whose temperature is adjusted to the vibration cutting unit 20. Yes.

  FIG. 10 is an enlarged plan view for explaining the machining of the workpiece W using the machining apparatus 10 shown in FIG. The tip portion 21a of the tool portion 21 vibrates at high speed, for example, in the YZ plane as already described. Further, the tip end portion 21a of the tool portion 21 is gradually moved by the NC drive mechanism 30 in FIG. 9 while drawing a predetermined locus, for example, in the XZ plane with respect to the workpiece W that is a workpiece. That is, the feeding operation of the tool unit 21 is performed. Further, the workpiece W, which is a workpiece, is rotated at a constant speed around the rotation axis RA parallel to the Z axis by the NC drive mechanism 30 in FIG. 9 (see FIG. 9). As a result, the workpiece W can be turned, and the workpiece SA is rotationally symmetric about the rotation axis RA with respect to the workpiece W, for example, a curved surface such as an uneven spherical surface or an aspheric surface, a phase element surface, or the like. Can be formed. At this time, by using the second stage 33, the tip of the cutting tool 23 of the tool portion 21 is rotated around the turning axis PX parallel to the Y-axis direction, so that the vibration surface (elliptical orbit EO) of the cutting tool 23 tip is rotated. ) To be substantially perpendicular to the surface SA to be formed on the workpiece W. As a result, the cutting point of the cutting edge of the cutting tool 23 can be maintained at approximately one point during processing, and efficient vibration transmission to the processing point and high-accuracy vibration cutting independent of the cutting edge shape can be realized. The accuracy can be increased and the surface SA can be made smoother. Further, during the processing of the workpiece W, since the pressurized dry air is injected at high speed from the opening 95a at the tip of the tool portion 21 toward the tip of the cutting tool 23, the cutting tool 23 and the work surface SA can be efficiently cooled. Not only can the temperature of the cutting tool 23 and the surface SA to be processed be within a certain range depending on the temperature and flow rate of the pressurized dry air. This pressurized dry air is introduced through a through-hole 95 that penetrates the axis of the tool portion 21 and flows through the cutting vibrator 82, the axial vibrator 83, the counter balance 85, and the like. The temperature of the body 82 and the like can be adjusted by the temperature and flow rate of the pressurized dry air. In this manner, by adjusting the temperature of the pressurized dry air, the temperature of the cutting vibrator 82 can be stabilized, and a highly accurate and highly reproducible cutting surface can be obtained.

[Third Embodiment]
Hereinafter, the molding die according to the third embodiment will be described. FIG. 11 is a diagram for explaining a molding die (optical element molding die) manufactured using the vibration cutting unit 20 of the first embodiment, and FIG. 11A is a fixed die, that is, a first die. FIG. 11B is a side sectional view of 2A, and FIG. 11B is a side sectional view of the movable mold, that is, the second mold 2B. The optical surfaces 3a and 3b of both molds 2A and 2B are finished by the processing apparatus 10 shown in FIG. That is, the base material (the material is, for example, cemented carbide) of both molds 2A and 2B is fixed to the chuck 37 as a workpiece W, and the standing wave is formed in the vibration cutting unit 20 by operating the vibrator driving device 50 and the like. The cutting tool 23 is vibrated at high speed. In parallel with this, the drive control device 40 is appropriately operated to arbitrarily move the tip of the tool portion 21 of the vibration cutting unit 20 in three dimensions with respect to the workpiece W. Thereby, the transfer optical surfaces 3a and 3b of the molds 2A and 2B are not limited to spherical surfaces and aspheric surfaces, but can be step surfaces, phase structure surfaces, and diffraction structure surfaces.

  12 is a cross-sectional view of a lens L press-molded using the mold 2A of FIG. 11A and the mold 2B of FIG. 11B. Although not shown, when the optical surfaces 3a and 3b of the molds 2A and 2B have a step surface, a phase structure surface, a diffractive structure surface, etc., the molding optical surface of the lens L is also a step surface, a phase structure surface, and a diffractive structure. It has a surface. Furthermore, the material of the lens L is not limited to plastic, but may be glass or the like. Note that the lens L can also be directly manufactured by the processing apparatus 10 of the second embodiment.

  Hereinafter, specific processing examples using the vibration cutting unit 20 and the processing apparatus 10 of the above-described embodiment will be described.

[First embodiment]
Here, the details of a working example using the vibration cutting unit 20 in which the vibrating body 82 and the holding members 82b, 82c, 85b, and 85c are integrally formed will be described. In the present embodiment, an apparatus similar to the processing apparatus 10 illustrated in FIG. 9 and using an ultra-precise processing machine having a pivot axis PX, is similar to the transfer optical surfaces 3a and 3b of the molds 2A and 2B shown in FIG. The transfer optical surface was processed by turning.

  As a material of the workpiece W as a mold as a workpiece, Microalloy F (HV1850) manufactured by Tungaloy was used. The shape of the aspherical optical surface to be processed is a deep concave optical surface having an approximate R concave of about 0.9 mm, a central curvature radius of 1.33 mm, and a maximum prospective angle of 65 °.

  The surface to be the optical surface of the work piece is processed into a concave spherical surface by electric discharge machining in advance, and further converted from an approximate spherical shape to an aspherical shape using a general-purpose high-precision grinding machine with an axial resolution of about 100 nm. Rough cutting was performed. In this rough grinding process, an electrodeposition grindstone was used, and while repeating shape correction, the shape accuracy was driven to about 1 μm in a short time and finished to an aspherical shape.

  Next, cutting finishing was performed by the processing apparatus 10 using the vibration cutting unit 20. The machining tip 23a of the diamond tool, that is, the cutting tool 23, has a rake face S1 at the tip (the rake face is a face that contributes to cutting of the cutting material in the cutting tool 23 as shown in FIG. 13). And an R bite having a tip arc shape. The arc radius at the tip of the rake face of the cutting edge provided at the tip of the processing tip 23a is 0.8 mm, and the relief angle α of the relief surface (the relief angle is the relief surface S2 or its extension line as shown in FIG. The angle formed by the tangent line at the cutting point and the tangent line of the machined surface at the cutting point is 5 °. The angle formed by the rake face at the cutting point is −25 °, and the cutting amount at this time is 2 μm. In the vibration cutting according to the present embodiment, vibration is performed in each of the axial direction and the bending direction, and the blade tip locus at the tip of the processing tip 23a performs a circular motion or an elliptical motion. As a result, cutting can be performed so as to scoop up on the rake face, so that the depth of cut can be increased several times even in ductile mode cutting compared to machining that is not vibration cutting. At this time, cutting was performed at a spindle rotation speed of 340 rpm and a feed rate of 0.2 mm / min to which a workpiece W as a workpiece was attached. In addition, the rotational axis PX of the stage to which the vibration cutting unit 20 was fixed was controlled, and the shape creation processing was performed so that the normal direction of the axial vibration direction and the design optical surface that is the target processing shape of the workpiece W coincided with each other. . When the processed surface was observed with a microscope, regular cutting marks that seemed to be the vibration period of vibration cutting were found in the same manner, but the scratches seen with the conventional vibration device were not seen. When the surface roughness was measured with a surface roughness measuring instrument HD3300 manufactured by WYKO, as shown in FIG. 14, regular cutting marks were arranged, and the average surface roughness was 2.65 nmRa. In FIG. 14, the horizontal axis indicates the position on the processed surface, and the vertical axis indicates the unevenness of the processed surface. The first die machining shape accuracy was improved to 0.05 μm PV by performing the second machining with a shape-corrected NC program in which the machining surface shape error of the first machining was corrected. Also, the second optical surface is cut using the tool used for the first optical surface processing and the NC program with shape correction, and surface roughness and shape accuracy almost equal to the first optical surface accuracy are obtained. Excellent process reproducibility was confirmed.

  On the other hand, the processing was carried out under the above-described conditions also with a conventional vibration cutting unit of a vibration body fixing method using a conventional screw pressing force. In the case of the comparative example, when the surface of the workpiece was observed with a microscope, scratches at irregular intervals were observed in addition to regular cutting traces that seemed to be the vibration period of vibration cutting. Then, when the vicinity of the scratch was measured with the same surface roughness measuring instrument as described above, the depth of the scratch was about 60 nm and the average surface roughness was 13.8 nmRa as shown in FIG. . In FIG. 15, the horizontal axis indicates the position on the processed surface, and the vertical axis indicates the unevenness of the processed surface.

[Second Embodiment]
Another machining example was carried out by turning using the same ultraprecision machine as the machining apparatus 10 illustrated in FIG. However, in this embodiment, since the blaze structure is processed, the revolving axis PX is not used, but the processing is performed with two axes of XZ. As the material of the workpiece, that is, the workpiece W, Microalloy F (HV1850) manufactured by Tungaloy was used. The shape of the aspherical optical surface to be processed is a shape having a blazed diffraction groove, and the amount of the blazed step is about 1 μm.

  The cutting tip 23a of the diamond tool, that is, the cutting tool 23 was a sword tip-shaped bite having a sharp tip apex angle of 30 °. The radius of the cutting edge of the rake face is 1 μm or less and the flank angle is 5 °. The angle formed by the rake face at the cutting point is −30, and the cutting amount at this time is 1 μm. In the vibration cutting according to the present embodiment, vibration is performed in each of the axial direction and the bending direction, and the blade tip locus at the tip of the processing tip 23a performs a circular motion or an elliptical motion. As a result, cutting can be performed so as to scoop up on the rake face S1, so that the cutting amount can be increased several times even in ductile mode cutting compared to processing that is not normal vibration cutting. The number of rotations of the main shaft is 500 rpm, the cutting depth is 100 nm, and the feed speed is 0. 1 mm / min.

  FIG. 16 shows an SEM observation image of an optical element molding die obtained by the processing method of this example. As you can see from the photo, the blaze has been processed as intended without sagging or burrs at the edge of the blaze. Further, the processed surface roughness is also a mirror surface in SEM observation. In a conventional comparative processing apparatus or vibration cutting unit in which a vibrating body is fixed so as to be sandwiched by a screw-shaped support, the diamond tool, that is, the processing tip 23a is made very sharp, so that processing is performed during blaze processing. The cutting edge of the cutting tip 23a was broken and could not be processed to the target blaze step. However, in the case of the embodiment, the holding rigidity of the vibrating body 82 can be improved, the cutting edge position at the time of vibration cutting is reproduced with high accuracy, and the irregular and large cutting edge position which was one of the causes of cutting edge breakage. There was no fluctuation, and the desired blazed shape could be processed. Further, a glass optical element capable of correcting chromatic aberration resistant to environmental changes was obtained by glass molding using the optical element molding die of the high hardness material.

  As described above, the present invention has been described according to the embodiment, but the present invention is not limited to the above embodiment. For example, in the vibration cutting unit 20, the shape of the tip 21a and the method for attaching the cutting tool 23 can be changed as appropriate.

  In the above embodiment, the set of vibrating bodies 82 and 85 are supported by the four holding members 82b, 82c, 85b, and 85c. However, the set of vibrating bodies 82 and 85 are supported by the two holding members 82b and 85b. It is also possible to support with. Further, when two or more node portions are formed on any of the vibrating bodies 82 and 85, a holding member similar to the holding members 82b, 82c, 85b, and 85c is provided at any one or more of these node portions. The case member 86 can be fixed.

  In the vibration cutting unit 20, the overall shapes and dimensions of the cutting vibrator 82 and the axial vibrator 83 can be changed as appropriate according to the application. Further, when the vibration cutting unit 20 is not heated so much, it is not necessary to worry about the dimensional change of the vibration body for cutting 82, and therefore it is not necessary to supply pressurized dry air. Further, in the gas supply device 60 of FIG. 9, instead of air, a gaseous fluid added as a solvent or particles in which oil or other lubricating elements are misted, an inert gas such as nitrogen gas, or the like can be used.

  Further, it is not necessary that the number of vibrating bodies 82 constituting the vibrating body assembly 20 is one as in the previous embodiments, and there are a plurality of vibrators for exciting such a vibrating body. May be.

  An example is shown in FIG. In the illustrated vibrating body assembly 1220, a second vibrating body 1282 is additionally joined to an axial vibrator 83 that excites the vibrating body 82 in the axial direction, and a second shaft is connected to the second vibrating body 1282. The direction vibrator 1283 is joined. Then, a third vibrating body 1382 is further bonded to the second axial vibrator 1283, and a third axial vibrator 1383 is further bonded to the third vibrating body 1382. Finally, The counter balance 85 is joined.

  These three axial vibrators 83, 1283, and 1383 are arranged at the antinodes of the axial vibration, and vibrate in the same phase to excite each vibrator and cause axial resonance. Thus, by connecting the vibrators 82, 1282, and 1382 and the vibrators 83, 1283, and 1383 in a cascade, the number of vibrators or vibration elements can be increased. The solid body 1220 can be put in, and the total mass of the vibrating body assembly 1220 is increased, so that the amplitude can be stably maintained against disturbance. In addition, since energy input for excitation is dispersed, heat generation from the axial vibrators 83, 1283, and 1383 is not concentrated, so that an increase in temperature of the vibrator assembly 1220 is suppressed.

  On the other hand, with respect to flexural vibration, two pairs of vibrators 84 and 1284 are provided at the antinodes of the vibrators 83 and 1283, but this also allows a larger vibration energy to be input to the vibrator assembly 1220. Therefore, it becomes easy to maintain vibration energy large and stably.

  Also in the vibrating body assembly 1220 as described above, in addition to the holding members 82b, 82c, 85b, and 85c, the flange portion shown in FIG. By providing 82e and 85e, it is possible to realize holding of a vibration body having extremely high rigidity.

  In addition, since the cutting force due to heavy cutting increases as the vibration energy is used, the holding method of the vibrating body assembly 1220 that has high rigidity and does not hinder resonance as in the above embodiment stabilizes the tool position with high accuracy. It is extremely effective in achieving this, and is very suitable for realizing highly accurate vibration cutting.

  In the above vibration cutting apparatus, turning has been mainly described. However, the vibration cutting unit 20 and the processing apparatus 10 shown in FIG. 1 can be modified for ruling.

Claims (7)

A vibration tool body capable of holding a cutting tool for vibration cutting and transmitting vibrations to the cutting tool when the cutting tool is held, and a vibration node related to at least flexural vibration when the vibration body body vibrates. A holding member that extends from the node portion in the normal direction of the flexural vibration surface of the vibrating body main body and is fixed to the node portion seamlessly. A cutting vibration body comprising: a flange portion formed on the distal end side of the holding member;
A case member having a support portion that houses the cutting vibration body and fixes the distal end side of the holding member;
A vibration cutting unit comprising:
The vibration cutting unit according to claim 1, wherein the flange portion abuts on the support portion from the inner surface side and has a fastening member for fixing the flange portion to the support portion. The vibration cutting unit according to claim 1, wherein the fastening member includes a plurality of screws, and the plurality of screws fixes the support portion and the flange portion at a plurality of locations. 2. The vibration cutting unit according to claim 1, wherein the fastening member is at least one screw member provided upright from the flange portion on the side opposite to the holding member. The vibration cutting unit according to claim 1, wherein the case member, the vibration body main body, and the holding member are formed of the same material. The vibration cutting unit according to any one of claims 1 to 4, further comprising: the cutting tool held by the vibration body main body; and a fixing unit that detachably fixes the cutting tool to the vibration body main body. The vibration cutting unit according to claim 5, further comprising a vibration source that vibrates the cutting tool through the vibration body main body by applying vibration to the vibration body main body. A machining apparatus comprising: the vibration cutting unit according to any one of claims 1 to 6; and a drive device that is displaced by driving the vibration cutting unit.